Method of harmonic selective signaling.



I PATENTED JAN. 15, 1907. W. W. DEAN. v METHOD OF HA RMONIO SELECTIVESIGNALING.

APPL IGATION FILED AUG. 9, 1905- s snnms snsm' 1.

No. 841,640. PATENTED JAN. 15, 1907.

W. W; DEAN.

METHOD OF HARD/IONIC SELECTIVE SIGNALING. APPLIOATIOH FILED AUG. 9,1905.

3 SHEETSSHEET 2.

3 SHEETS-SHEET 3.

FPATENTED JAN. 15, 1907. w. w. DEAN.

METHOD OF HARMONIG SELECTIVE SIGNALING. APPLICATION FILED AUG. 9, 1905.

U x w w ML a M 5+--- MM A @W w. 5 K \R N heretofore designed two methodshave been UNITED STATES PATENT OFFICE."

WILLIAM W. DEAN, OF E LYRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRICCOMPANY, OF ELYRIA, OHIO, A CORPORATION OF OHIO.

METHOD OF HARMONIC SELECTIVE SIGNALING- Specification of Letters Patent.

Patented Jan. 15, 1907.

Original application filed Apri117, 1905, Serial No. 255,961. Dividedand this application filed August 9, 1905. Serial No. 273,461.

To all whom, it may comgern:

Be it known that I, WVILLIAM W. DEAN, a citizen of the United States,residing at Ely.- ria, inthe countyof Lorain and State of Ohio, haveinvented certain new and useful Improvements in Methods of HarmonicSelective Signaling, of which the following is a s ecification,reference being had therein to the accompanying drawings.

My invention relates to improvements in party-line telephone systems,and has for its. object, generally speaking, the rovision of an improvedharmonic system 'or selective signaling and an improved method ofoperation therefor.

My invention, as I shall present it, comprises both the method and oneform of apparatus or apparatus embodied in one form by which the methodmay be practiced. The method alone will be claimed herein, however, theapparatus being claimed in a separate application, filed April 17, 1905,Serial No. 255,961, of which the present case is a division.

In harmonic selective-signaling systems employed. By one a reed tuned toexact pitch was relied upon to close a circuit, and by the other amechanical signal included directly in the harmonic circuit wasovertuned or undertuned to allow for losses or acceleration inoperation. A third method, that of exact tuning of the mechanicalelements, has been attemped at divers times, but has never succeeded tomy knowledge prior to my present invention. The first and second methodsneed not be considered here, my present invention relating particularlyto the third method. Systems of this type have heretofore beenunsuccessful and uncommercial for several reasons. It was founddifficult if not impossible to operate a bell having a tongueconstituting a tuned reed by means of the ordinary pulsating oralternatingcurrent of a frequency or a pitch corresponding to that ofthe bell-reed. The weight of the hammer or clapper, the manner ofapplying the attractive force of the magnet, and the reactive effect ofthe vibrating gong have always proved sources of trouble in'attemptingto reach a perfect tune. I have discovered, however, that it is possibleby properly applying the energy of the ringing-current to positivelyovercome and render neghble the bloc disturbing forces to which'I havereferred. In other words, without unduly increasing either the voltageor the ampere-turns in the ringer-magnets I apply the energycumulatively in such manner as to reach an efiective totality ofsuiiicient magnitude to render irlnall losses and disturbing elementsnegligi- Expressed in a few words my system employs a polarized ringerhaving its armature mounted in a neutral position upon a strong spring,so strong that ordinary ringing-current momentarily applied produces noeffect. Only when current of the proper frequency has passed through theringer-coils for 2. Ion enough period to start up the armature an thetuned clapper do the gongs receive any stroke. I tune the clap; rods orreeds by fastening thereon (slappers formed'in cylindrical shape and ofdifferent lengths and Weights.

My invention is illustrated in the accompanying drawings, in whichFigure 1 is a front view of aringer with gongs mounted complete. Fig. 2is an end view of the same. Fig. 3 is a top planview with the gongsremoved. Fig. 4 is a bottom plan view. Fig. 5 is a perspective view ofthe clapper-rod and connected parts removed, and Fig. 6 is a diagram ofa subscribersline having four stations equipped with my invention andthe cooperating central office apparatus.

l will first describe the mechanical structure of my ringer and thenpoint out the method of its employment.

Referring to Figs. 1 to 5, A designates a pair of magnet-spools withcores 0, a, secured by screws a upon the yoke B. At the lower ends ofthese cores is carried a secondary yoke B, the same being secured by thenuts 6 b upon the sleeves b secured to the magnet-heads or, in any othersuitable manner.

The yoke B has front and rear drop portions 6 I), each slotted, asindicated at b for the rece tion of the ends 0 c of the armature or bolt0; On each of these is fitted a lock-nut c". This block and itsconnected arts are best shown in Figs. 4 and 5. The block O ispreferably squared throughout that portion of its length which liesbet-ween the parts b 17*, its ends being reduced and threaded at c c.The squared portion is milled out on one side to receive the shortu'sted with regard to the poles a of the carried upon metal segments 6*,each pivoted sary, and this adjustment, moreover, must be solid, so thatwhen the parts are once set leaf-spring C. To hold this in position onthe block, a short bar c -1s clamped upon it by means of screws 0Secured upon the spring above the block is the armature C This is madeof pressed metal in two halves '0', each having an upstanding flange cor 0". These two flanges are set upon opposite sides of the spling andsecured together through the latter by means of rivets a Each flange isformed with a semicylindrical channel to one side of the spring and anout side rivet c the channels when put together receiving theclapper-rod G which is thus secured rigidly to the armature structure bythe common bridging means. At its upper end the clapper-rod is fittedwith the clapper C, composed of a length of tubing solidly driven ontheirod. The length of this tubevaries according to the tune desired. Inassembling the device the ends of the block C. are inserted from beneathinto the slots 6 the clapper-rod at the same time passing up through anopening 0 in the yoke B and lying in front of the upper yoke B betweenthe' gongs G. The armature having been adringer-magnet the nuts 0are-set up tightly, and thereafter the only movement of the armaturepossible to make is that permitted by bending the spring G Secured uponthe upper yoke and passing down behind the magnets into contact with therear nut c is. the permanent magnet M, and as the upper yoke B and theblock C, with its parts, are of iron it follows that a very efficientmagnetic circuit is thus obtained, the only breaks in which are theair-gaps between the poles a and the armature O. The gongs G are mountedupon the posts 9, the latter being at b u on a suitable bolt passingthrough the yoke At its front edge 1) each segment is provided withgear-teeth meshing with the worm 6 out on the stem of the bolt b. :ihisbolt b has its ends supported in dro bearings formed in hook shape onthe yo e B, as shown at b", Figs. 1, 2, and 3. In or der to get the bestresults with this ringer, an accurateadjustment of the gongs isnecesthey will remain undisturbed by the forcible action which Icontemplate. The gongposts pass u from the segments through lateralenlarged openings 1) in extensions 1) on the yoke B. By means of asuitable wrench applied to the head of either bolt 1) the same may beturned, and the worm thereon will move the segment one way or the otherand with it the gong-post and gong.

It will be observed that the construction of my rin er-throughout issuch as to make it very solid and substantial. Its depreciation througha long period of time is intended to I be neglibleand its operationuniformly eflil senses cient throughout its life. It is so designed thatit may be substituted for an ordinary bridging-ringer or, in fact, forany ringer at any station having parts of standard type.

The sizes and general arrangement of parts are such that no specialfeatures are required.

K and ringing-keys K, K K and K. A

subscribers line 1 2 terminates at contact a of the cut-off relay N, bywhich the line is adapted normally to be connected to a sigrial-relay L,controlling a lamp Z, and when a plug is inone of the jacks J or J to becon nected thereto and disconnected from the relay. The cord-circuitcontains the four relays R, R, R and R bridged in pairs across the twoends of the circuit, eachpair jointly controlling one of the supervisorylamps r r. Current is furnished by central batteries Q. From one ofthese the wire 12 extends as a common return for the line-relays, andalso connected through resistance r by branch 11 as a common return forthe selective ringing-keys, battery-current being thus supplied to thesleeve side of line for the cut-off relay N while ringing. Each of theselective keys K, K K and K is connected on one side by wire 7, 8, 9, or10 to a generator giving a particular frequency,so that by using the proor key any one of the four frequencies may e thrown upon the line.

At the four subscribers stations VV, X, Y,

and Z the four ringers are all tuned to respond to differentfrequencies. At station IV the tubular clapper is long and heavy, thisstation being called by the lowest frequency current. At stations X and.Y the length and weight of the clapper is successively reduced, and atstation Z it is shortest and lowest or' all, this station being calledby the current of highest frequency.

It is to be understood that momentary current of right orwrong frequencywill not effectively move any of the four armatures. If the currentcontinues to flow for a brief period, however, the armature at thatstation which is tuned to respond to the selected frequencygraduallygets into motion. As it is pulled over the strength of themagnetic pole strongly increases, and in order to get a powerful effect,and, in'fact,relying as I do upon what might be termed sheer bruteforce, I discard all delicate adjustments and safeguards and strip themagnet-pole, so that the armature may come into direct contact with it.I thus get a maximum pull and a maximum effect on'the clapperjust when Ineed itthe.-x-most-that is, at the instant of possible interference dueto reactive vibra-Hyv tion fromthe gong. Thus I start myselec; 1 30 tiveringerZbytuning it exactly, so that it will owing to their being out oftune, er of course unafiected, and Imay add that the strength a perfectresonance to overcome l neirstifiness.

' plain.

actuate them, then by means of suitable currentstarting the action of aselected unit and cases in conjunction with the windings of the senaterespond before striking the gong, and after it has once started tovibrating I provide a strong enoughaction to positively overcome anyinterference. Those ringers, however, whichhave not started into goodvibration,

of the springs C is such that it .akes almost The method I set forthwithout regard to the specific apparatusemployed will now be t consistsin providinga number of positively-tuned elements normally held inactiveand requiring considerable energy to having started it thereafter bysupplying sufficient energy forcing it into full operation.

It will be noted that I have shown condensers in the bell branches at mysubstations. I employ these condensers in some magnets for the purposeof electrically tuning the branches. While my system is preferablyoperative Without this, it is particularly adapted for use in commonbattery systems, the small leakage through the branches not tuned toreceivr a particular ringing-current being negligibon account of thestitfness of the springs (3' Thus the ringer at the desired station.only will get current enough to start its armature into vi brationirrespective of its mechanical tune, and, as I have stated in. theforegoing, this initial vloration is essential to full actuation, as theflOI'IilE pcanj noi the armature is too far from the pole i a magnet forinstar neous pulls to against the stall of the springs.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. The method of selectively operating electrical-- apparatus whichconsists in the following steps: first, tuning the movable parts of anelectromagnet so that they will absorbenergy when imparted at intervalsof the proper frequency; second, initially movquency imparting'initialmotion to the parts or any desired ringer; and. third, exposing theparts when so moving to the maximum magnetic effect of the magnet so asto insure .proper actuation of the parts and to render reactiveinterferences negligible, substantially as described.

3. The method of selective signaling, which consists in tuning themovable parts ofan eiectromagnet to respond to a given frequency,feeding a current of constant strength and proper frequency to saidmagnet to initially move said parts, and exposing said parts when somoving to the maximum magnetic effect of said magnet so as to insureproper actuation and to render reactive interference negligible.

In stimony whereof I afiix my signature p we of two xvi tnesscs.

WlLLlAlvl 'W. DEAN.

Witnesses A. D, T. LIBBY, Geo, SoovrLLn.

